Wood chipper construction



July 16, 1968 K. LEDERGERBER WOOD CHIPPER CONSTRUCTION Filed May 15,1967 IN VEN TOR.

I; /Kwu Z. EOFRGERBER JM .i@ Y 32 7701?! Y5 United States Patent3,392,763 WOOD CHIPPER CONSTRUCTION Karl Ledergerber, Box 556, Wadley,Ga. 30477 Continuation-impart of application Ser. No. 439,325,

Mar. 12, 1965. This application May 15, 1967, Ser.

6 Claims. (Cl.,144176) ABSTRACT OF THE DISCLOSURE A wood chipperapparatus is provided with an improved mounting of a chipper disc, andan improved feed spout construction is provided for receiving whole logsfor a chipping action. The chipper disc is mounted on a shaft which iswholly supported by bearings on one side of the disc only, and thisarrangement permits a mounting of longer cutting knives on a face of thedisc. The feed spout is constructed to receive whole logs, and aplurality of anvils carried by the feed spout are arranged on a curvedpath to coact with the chipper disc.

Related application This application is a continuation-in-part of mycopending application Ser. No. 439,325, filed Mar. 12, 1965, now PatentNo. 3,332,461.

Background of invention This invention relates' to an improvement inrotary disc chippers and is particularly concerned with an improved feedspout and chipper disc arrangement for use with rotary disc woodchippers.

In the wood pulp industry it is necessary to reduce wood stock such aslogs or slabs of wood to a chip form. It is desirable in producing suchchips to obtain a-chip product which has certain uniform characteristicsof size and quality in order to provide for better cookingcharacteristics of the chip product. Therefore, it is important that thewood stock be cut cleanly with little bruising or squeezing of theresulting product, and it is important to obtain a uniform chip productat a maximum rate of production.

As described in my copending application Ser. No. 439,325, now PatentNo. 3,332,461, it has been the practice in producing such a chip productfrom wood stock to utilize a rotary disc chipper apparatus of the typeshown in US. Patents 1,438,943 and 3,047,244. Such apparatus includes achipper disc mounted for rotation in a vertical plane, and a number ofcutting knives are mounted on one face of the disc. The cutting knivescoact with a stationary bed knife, or anvil, in such a way that ascissors action results between the rotating knives and the stationaryknife. Wood stock in the form of logs or slabs is conveyed to thevicinity of the chipper apparatus, and the wood is then delivered into afeed spout associated with the chipper apparatus. The feed spoutcommunicates with the face of the chipper having the cutting knives, andthe feed spout serves to support the wood stock while the stock is beingdelivered and drawn into the cutting face of the rotary disc. Otherprior art on this subject as developed in the examination of mycopending application, includes the U5. Patents 1,942,675, 2,712,974,3,069,101 and 3,123,311.

Summary of invention The present invention is directed to improved feedspout and chipper disc constructions for use in apparatus of the typedescribed above. It has been found that the improved structures of thisinvention result in better support for logs so that a maximum cuttingefiiciency is attained and a more uniform chip product is produced.

In accordance with the present invention, the feed spout of a chipper isconstructed to carry a plurality of stationary anvils. These stationaryanvils are arranged in a curved path which approximates the curvature ofa log at a plane which is cut at an angle to the longitudinl axis of thelog. Further, the plurality of anvils provides for a construction whichis more economically and easily produced for log handling chippers, andrelatively large diameter stock material can be handled at an improvedcutting rate for a given apparatus.

In addition, the present invention provides for an improved mounting ofchipper discs associated with any rotary disc apparatus of the typedescribed above. Prior chipper disc mounting arrangements have providedfor a bearing support at each end of a shaft which carries a chipperdisc for rotational movements within a housing of the wood chipperapparatus. The cutting knives which are normally positioned on one faceof the chipper disc have been limited in their individual lengthsbecause it was necessary to permit the passage of the shaft through theentire disc structure and past the mounted positions of the knives.Also, prior art bearing supports have interfered with the size andlocation of feed spouts. The present invention provides for a novelmounting of a chipper disc within a housing wherein the shaft upon whichthe disc is carried for rotational movements is mounted in bearingsupports located on one side only of the disc. This means that thesurface of the disc which is used for carrying cutting knives may be asurface which is opposed to the positions of the bearing supportmembers. Thus, the knives may be longer in length and may approach thecenter axis of rotation for the disc in an arrangement which providesfor substantially improved cutting action for each individual knife.Also, the positioning of the feed spout relative to the housing may besubstantially improved for chipper apparatus of this type.

Other advantages of the improved feed spout and chipper discconstructions of this invention will become apparent in the moredetailed discussion which follows, and in the discussion reference willbe made to the following drawings.

Brief description of the drawings FIGURE 1 is a top plan view of a woodchipper apparatus, showing a top section of the apparatus removed so asto illustrate an improved mounting of a chipper disc within a housing ofthe apparatus, and

FIGURE 2 is an elevational view of the chipper apparatus of FIGURE 1,illustrating an improved feed spout construction for handling logs.

Detailed description of invention The wood chipper apparatus of thepresent invention may be of any typical construction, and may includethe constructional features described in my copending application Ser.No. 439,325. The descriptive material in my copending application isintended to be included as part of the present description by referencethereto. Such a wood chipper apparatus is shown generally at 10 in thedrawings. The chipper apparatus 10 includes a housing having a baseportion 12 and a cover portion which may be made up of sections 14 and16. The cover section 14 may be pivotally mounted by a hinge 18 so thatit may be tilted and opened relative to the section 16. Thus, the coversection 14 may swing open to permit an easy access to the interior ofthe chipper apparatus. When the section 14 is in a closed position itmay be clamped or locked to the adjoining cover section 16 by anysuitable means. A chip removing stack 22 is provided for removing thechip product out of the apparatus.

Within the housing, a rotating chipper disc 24 is mounted on ahorizontal axis for rotation in a vertical plane. A horizontallydisposed axle means 26 carries the chipper disc 24 and provides the axisof rotation for the disc. The axle means 26 may pass into a centralportion of the disc 24, but the axle does not extend beyond a front face32 of the disc which carries knife elements 34. A pair of bearingsupports 36, such as pillow block bearings of well known construcfion,may be provided for supporting the entire axle and disc assembly forrotation about a horizontal axis. An important feature of the presentinvention is to mount the entire axle and chipper disc assembly with allbearing supports located on one side only of the chipper disc. Thisfeature provides for the use of longer knife elements 34 on a cuttingface 32 of a chipper disc without any interference from an axle shaft orbearing supports on the cutting side of the disc. The chipper disc 24may include a hub element 38 which is secured to the disc for providinga tight mounting of the disc on an end of the axle 26. Means forrotating the disc may include a motor and drive belt means of well knownconstructions, as exemplified in the above mentioned patents or in mycopending application. The driving means is preferably positioned on thesame side of the chipper disc as are the pillow block bearings 36.

Because of the improved arrangement for mounting a chipper disc with allbearing support means located on one side only of the disc, it ispossible to provide a better placement and construction for knifeelements 34 on a cutting face of a disc. Referring to FIGURE 2, it canbe seen that the knife elements 34 are relatively long, compared toprior art arrangements, and the illustrated embodiment shows four knifeelements 34 placed about a disc face, although any suitable number ofknives may be used. The four knife elements 34 are placed atsubstantially right angles to one another, however, each knife elementis offset slightly from a perfectly aligned position with the centralaxis of the chipper disc. Each knife element 34 is fixed to the face ofthe disc so that a cutting edge 40 leads the knife in its movement withthe rotation of the disc. The end 42 of each cutting edge slightly leadsan end 44 of the same knife as related to a line drawn through thecentral axis of the disc and along the plane of the cutting face 32. Theknife element 34 may be bolted or otherwise affixed to the front face ofthe disc so as to be replaceable when worn. Also, each knife element 34may be mounted over an opening 46 which is formed completely through thechipper disc in a well known manner to provide for a movement of chipsaway from the cutting edge of the knives and through the disc.

In addition to the elements just described, the chipper apparatusfurther includes an inlet means for feeding stock material to thecutting face of the rotating chipper disc. The inlet means is in theform of a feed spout 50 which is shown as a horizontally disposedtubular member which leads into a side wall of the chipper apparatushousing so as to communicate at an angle with the lower half of therotating disc face 32, In this manner, an opening is provided forfeeding logs or other stock material into the cutting face of therotating disc.

The feed spout 50 is preferably circular or oval in its cross section soas to handle the circular configurations of whole logs which are to bereduced in the chipper apparatus. A terminal end of the feed spoutenters the housing of the chipper apparatus so as to present the end ofa log against the rotating face 32 of the disc 24. With the discrotating clockwise, as viewed in FIGURE 2, it can be seen that thecutting edges 40 of the disc move across the exposed end of the loggenerally from right to left so as to slice chips from the log. Asalready discussed, the cutting action of chipper devices of this typeresults from a movement of a plurality of knives past fixed anvils so asto accomplish a scissors-like action between the knives and the anvils.The present invention is concerned with providing a novel arrangement ofa plurality of anvils so as to improve the cutting action against wholelogs, as

. '4 compared to previous arrangements for cutting slabs and other formsof wood stock.

Although it is kown to provide feed spouts having tubular inlet memberswhich introduce stock material into chipping apparatus, the usualfunction of such feed spouts is to merely carry or convey stockmaterial, and there has been no provision for an improved cutting actionor cooperation of an end of such feed spouts with a chipper discrotating in a vertical plane. Also, it is known to provide single pieceanvil elements having curved surfaces for assisting in the support andconveying of curved stock material into some form of chipper apparatus.However, prior devices have not been as efficient to operate nor aseconomical to produce as the improved feed spout and anvil structure ofthe present invention. Referring to FIGURE 2, it can be seen that thefeed spout 50 is horizontally disposed to enter the chipper apparatushousing at an angle, and thus, a circular feed spout will form acommunication through an opening in the vertical housing wall. Theopening which is formed through the housing wall to receive the feedspout 50, and to carry logs therethrough, has essentially an ellipticalshape, as illustrated. As viewed in FIGURE 2, the left hand side of theelliptical opening through the housing Wall is provided r with a seriesof separate anvil elements 52 which are disposed about the curved innerterminal end of the feed spout 50 so as to provide fixed surfacesagainst which the cutting knives 34 can move a log which is beingreduced to chips. The elements 52 make up the anvil means for the feedspout construction, and the anvil elements start at a top point of thefeed spout and are placed downwardly and outwardly, as illustrated,until they reach a midpoint of the longitudinal axis of the feed spout.From there, the elements 52 are placed downwardly and inwardly untilthey reach a bottom point on the circular opening formed through thehousing wall. Thus the fixed anvil means of the present invention is inthe form of an anvil which is made up of a plurality of single anvilelements placed along a curved path which describes an ellipse or someother preferred curve. The single anvil elements 52 are easilymanufactured and heat-treated because they are formed with straightsurfaces, and thus, no costly machining and treating operations arerequired in the manufacture of the elements 52. However, even though theelements 52 are formed with straight surfaces, they are disposed aboutthe inner end of the feed spout 50 so as to form an essentially curvedanvil surface against which a log may be placed While it is beingreduced to chips. The anvil elements 52 may be mounted at the inner endof the feed spout 50 in any convenient manner, and a preferredconstruction has been illustrated. Plate members 54 are affixed to avertical portion of the chipper housing wall, and each plate element 54includes a curved inner edge which defines a portion of the ellipticalopening formed through the housing wall. The anvil elements 52 are thenbolted, or otherwise afiixed directly to the plate members 54 so as tofollow the curved edges of the plates. When all elements are in place,an essentially curved anvil means is presented toward the inside of thechipper apparatus so as to cooperate with the movement of knives 34 pastthe position of the anvil.

Also, it can be seen from FIGURE 2 that the feed spout 50 and theopening through which it communicates into the chipper apparatus may beideally positioned so as to receive a full sweep of the cutting edges ofeach knife element 34. This positioning is further made possible by theremoval of any bearing support structures which would otherwiseinterfere with the location of a feed spout into one side of a housingfor a chipper apparatus.

With the apparatus which has been described and illustrated, a log canbe introduced into the feed spout 50 for reduction to chips. Once thelog is moving along the length of the feed spout, one end of the logwill be introduced into the rotating, cutting face 32 of the chipperdisc 24. As soon as the knife elements 34 contact an end of the log, thelog will be pushed against the anvil means which is formed from theplurality of anvil elements 52, and then, a scissors action will causethe log to be reduced to chips as the knives sweep past the log end in aclockwise direction. It has been found that the cutting action of theknives, as coupled with the cooperation of the curved anvil means 52results in the log being drawn into the chipper apparatus. Thus, theentire log is advanced into the cutting face of the chipper disc 24until it has been completely reduced to chips.

With the invention just described, it is possible to handle logs withoutfirst reducing them to slabs or other configurations, and a moreefficient and economical chipping action and rate are attained. Althoughthe invention has been described with reference to a preferredembodiment, variations will become apparent to those skilled in the art,and such variations are intended to be included within the scope of thepresent invention, as claimed.

What is claimed is:

1. In a wood chipper apparatus of the type having a chipper disc whichrotates in a vertical plane, said disc having a plurality of cuttingknives mounted on a face thereof, the improvement comprising:

a tubular feed spout extending into the wood chipper apparatus fordelivering a log into the face of the chipper disc having the pluralityof knives mounted thereon, said feed spout being disposed on asubstantially horizontal plane and at an angle to the chipper disc sothat logs being fed through the feed spout are drawn into the chipperapparatus and reduced to chips by the action of the knives on thechipper disc, and

a curved anvil means carried by a side wall of the feed spout forcoacting with the cutting knives of the chipper disc, said curved anvilmeans further comprising a plurality of anvil elements which arearranged on a curved path which essentially follows a portion of thecurvature of the tubular feed spout at its terminal end portion whichextends into the wood chipper apparatus.

2. The improvement of claim 1 wherein said plurality of anvil elementsare arranged on a curved path which describes a portion of an ellipse.

3. The improvement of claim 1 wherein said plurality of anvil elementsare mounted on vertical portions of a housing which encloses saidchipper disc.

4. The improvement of claim 1 wherein said chipper disc is mounted at anend of a horizontally disposed axle means which is mounted for rotationin bearing means, said bearing means being positioned only on a side ofthe chipper disc which is opposed to the face of the disc which carriesthe cutting knives.

5. In a wood chipper apparatus of the type having a chipper disc whichis mounted for rotation within a housing, and a plurality of knivesmounted on a first face of the chipper disc, the improvement in themounting of said disc which comprises:

an axle means which is mounted for being driven so as to rotate thechipper disc, and means to secure the chipper disc to a terminal end ofthe axle means so that the axle does not extend beyond said first faceof the chipper disc, and

bearing means for supporting said axle means, said bearing means beingpositioned only on an opposite side of the chipper disc from said firstface.

6. The improvement of claim 5 and including driving means for rotatingsaid axle means and said chipper disc, said driving means beingpositioned on said opposite side of the chipper disc.

References Cited UNITED STATES PATENTS 1,942,675 1/1934 Wigger et al.

2,174,593 10/1939 Pelot et al 144176 XR 2,299,248 10/ 1942 Ottersland144-176 XR 3,061,207 10/1962 Clark 241-92 WILLIAM W. DYER, JR., PrimaryExaminer. W. D. BRAY, Assistant Examiner.

